Re: [PATCH 2/3] perf/core: introduce pmu_event_flags and PMUEF_READ_CPU_PKG

David Carrillo-Cisneros
2016-08-04T17:30:32Z

>> Introduce the flag PMUEF_READ_CPU_PKG, useful for uncore events, that
>> allows a PMU to signal the generic perf code that an event is readable
>> on the current CPU if the event is:
>> - active in a CPU in the same package as the current CPU (local CPU)
>
> Ok that I get..
>
>> - not active but is attached to a CPU (i.e. event->cpu != -1) in the
>> same package as the current CPU.
>
> but this, not so much. Why would you want to read an inactive counter?

Uncore counters are active even if its event is not.